Internally, there are plenty of changes too. The QB10 uses a combination of hardwiring (with mono-filament solid-core conductors) and a single, heavily plated circuit board, just like the QB8. Although many of you might assume that hard-wiring would produce superior results and, let’s face it, Nordost have plenty of wire to go that route if they choose, the choice of a PCB, physically and electrically star-grounded circuit. Constantly developed across the different QB8 models, the PCB used is optimised for high current capacity, mechanical stability and precise routing of the tracks. Compare that to the random, rat’s nest of cabling that results from a point-to-point hook up and you can begin to understand why a PCB-based solution can offer superior results.
The board is laid out symmetrically around the centre line, with a single, off-set Primary Earth point, the central point for the signal grounds and the socket to which your pre-amp or integrated amp should be connected. There is, however, one instance in which users can and should change this arrangement. There is a switch, tucked away on the underside of the unit, beneath a push-fit cap, that allows you to tie together the two central sockets, creating a pair of ground connections. If you have a dual-mono pre-amp such as a CH Precision L1 Mono, with two power cords (or you are bi-amping with a pair of integrated amps) this ensures that both channels see an equal ground impedance. It’s a feature that might be rarely used, but one that demonstrates just how field experience with the QB8 has informed the design and features onfthe QB10.
As I’ve already mentioned, as well as distributing the AC power, the QB10 also applies a number of other technologies. Over the years, Nordost has launched a number of modular accessories designed to mitigate RFI interference and correct the AC waveform. The original QX units were standalone boxes that evolved into the QPoint distributed system, while the QSine and QWave were always plug-top modules. The problem with the latter was that, despite their audible effectiveness, they ate up socket space in the QB8, space that was already under pressure. The QB10 changes all that, by incorporating its own, internal QPoint technology, while also providing internally mounted QSine and QWave generators. Users can engage QS, QW, neither or both for either side of the board independently, allowing them to best configure the supply for the functionality of the units connected. Along with a separate grounding post to allow connection to an external, parallel ground, such as one of the various QKore units, that makes for a highly tuneable and adaptable set up. Put that lot together and in some respects the QB10 actually represents seven products in one, plus a bunch of sophisticated mechanical grounding devices. Which helps explain the substantial hike in price over the QB8. The QB10 will cost you close to $18,000 USD, placing it slap bang alongside both other high-end offerings and Nordost’s own Reference level products, the Valhalla2 and Odin 2 cables. It also makes for a complex and protracted review period. With so many topological variations available, running through them all simply ends up reading like a laundry list. So, I’ll start with the performance of the QB10 and then look at the configuration I settled on and the options within it.
Initial set up…
There are a couple of choices to make when installing the QB10. The first, mentioned above, involves deciding whether to split or combine the Primary Earth connections. That’s simply depends on the precise nature of your system and in most cases you’ll install the unit as delivered. In the Music Room system, I connected the Wadax components to one bank of sockets, the turntable, phono-stage and line-stage to the other, along with an extension running to the power amps, fed from either a QB8 or a second QB10. The Wadax components present an interesting case in point. The Ref DAC uses two independent power supplies, each with a ground lift. I ran one supply grounded and lifted the ground on the other, which reduced noise and produced a more focussed and dynamically definite sound. The remaining three sockets fed the Reference PSU, the Atlantis Reference Transport and the power supply for the locally sited Reiki SuperSwitch. But if you were running a dedicated QB10 solely for the digital components, you could pair up the second Primary Earth socket and connect the Ref DAC’s power supplies in parallel, for potentially even better results. I haven’t tried this, but I’m certainly tempted to…
